Optical signal processor, method of its control, method of its designing, and method of its production

摘要

An optical signal processor according to the present invention is an optical circuit of a lattice configuration. Its basic circuit structure comprises 3 dB directional couplers, two optical waveguides with equal optical path lengths, and two optical waveguides with different optical path lengths (an optical path difference of about 1 to 50 mm). Phase controllers for performing phase shift are provided on the optical waveguides. The portions with equal optical path lengths function as variable directional couplers, and variable directional couplers having arbitrary coupling rates can be constructed by changing the phase controllers on the optical waveguides with equal optical path lengths. As for an adaptive filter, there is adopted a construction in which a photodetector for withdrawing part of output is provided at the output port, and a feedback electric wiring for feedback control is laid.